When it comes time to upgrade your electrical panel, one of the first questions your electrician will ask is: do you want 100-amp or 200-amp service? Here’s what actually matters when making that decision.
What the Numbers Mean
Amperage is your panel’s capacity — how much electrical current it can handle at once. A higher amp rating means more headroom for running multiple things simultaneously without overloading circuits.
- 100A — Adequate for smaller homes (under 1,500 sq ft) with standard appliances and no EV charger or heavy equipment
- 200A — The current standard for most new construction and the right choice for larger homes or high-demand setups
Go With 200A If You Have Any of These
- Electric vehicle charger (current or planned)
- Electric range or oven
- Central air conditioning
- Electric water heater or HVAC heat pump
- A workshop, garage, or home office with dedicated equipment
- Any plans to add square footage
The honest answer is: if you’re upgrading anyway, go 200A. The cost difference between 100A and 200A service is usually only a few hundred dollars during installation, but upgrading again later means paying full labor costs twice.
What About 400A?
400-amp service exists and makes sense for large homes, multigenerational setups, or if you’re running significant equipment. Most single-family homes don’t need it, but it’s worth asking your electrician if you have unusual requirements.
The Bottom Line
For most homeowners doing a panel upgrade today: 200A is the right call. It’s the standard, it future-proofs your home, and the marginal cost over 100A is small relative to the total job.